Method for making a solid state semiconductor device

Abstract

A method for making a solid state semiconductor device includes: providing a substrate; forming a buffer layer on the substrate; forming a first epitaxial layer on the buffer layer; forming a surface-textured second epitaxial layer on the first epitaxial layer by chemical vapor deposition; and forming a solid state stacked layer structure having a PN-junction type light-emitting part on a textured surface of the second epitaxial layer.

1 . A method for making a solid state semiconductor device, the method comprising steps of:
 (a) providing a substrate;   (b) forming a buffer layer on the substrate;   (c) forming a first epitaxial layer on the buffer layer;   (d) forming a second epitaxial layer on the first epitaxial layer by chemical vapor deposition, the second epitaxial layer having a textured surface; and   (e) forming a PN-junction type light-emitting structure on the textured surface of the second epitaxial layer.   
     
     
         2 . The method according  claim 1 , wherein step (d) is performed at 750˜950 degrees centigrade. 
     
     
         3 . The method according  claim 2 , wherein step (d) is performed at 800˜900 degrees centigrade. 
     
     
         4 . The method according  claim 1 , wherein step (d) is performed by metal-organic chemical vapor deposition. 
     
     
         5 . The method according  claim 1 , wherein the textured surface of the second epitaxial layer comprises a plurality of hexagonal pyramid pits formed therein. 
     
     
         6 . The method according  claim 1 , wherein the second epitaxial layer is made of polycrystalline materials with hexagonal system structure. 
     
     
         7 . The method according  claim 1 , wherein the second epitaxial layer is a semiconductor layer of gallium nitride. 
     
     
         8 . The method according  claim 1 , wherein the material of the substrate is selected from a group consisting of sapphire, gallium nitride, aluminum nitride, gallium aluminum nitride, silicon carbide and silicon. 
     
     
         9 . The method according  claim 1 , wherein the buffer layer is a semiconductor layer of group III nitrides. 
     
     
         10 . The method according  claim 1 , wherein step (e) comprises:
 forming a n-type semiconductor layer of group III nitride on the textured surface of the second epitaxial layer;   forming an active layer of group III nitride on the n-type semiconductor layer; and   forming a p-type semiconductor layer of group III nitride on the active layer.